The Constitutional Court of the Republika Srpska has ruled in favour of holding a controversial referendum over whether to continue celebrating the formation of the Serbian autonomous region.

Signboard of the Constitutional Court of the autonomous region of the Republika Srpska in Banja Luka.

The Constitutional Court of the Republika Srpska (RS) in Bosnia and Herzegovina has ruled in favour of allowing Bosnian Serbs to hold a controversial referendum on whether to continue celebrate the region's national day on Sept. 25, despite this previously being blocked by Bosnia's Constitutional Court.

The controversial Day of Republika Srpska, marking the 1992 establishment of the autonomous region, on January 9 – is also the date of a Serbian Christian Orthodox holiday.

On July 15, the RS National Assembly passed a resolution allowing the referendum, which has been backed by all Bosnian Serb parties.

Having ruled in favour of the referendum, the Council for Protection of Vital National Interests of the Republika Srpska Constitutional Court in Banja Luka stated the decision would not endanger the "vital national interests" of the Bosnian people.

Bosnia's Constitutional Court in Sarajevo previously ruled that holding a referendum on Sept. 25 is unconstitutional and will harm non-Serb residents of the entity.

The court's decision has been harshly criticised by ethnic Bosniak (Bosnian Muslim) politicians, who say it violates the Dayton Agreement that ended the war in Bosnia between 1992-95, which led to hundreds of thousands dying in the country.

Associate Professor at the International University of Sarajevo, Metin Boşnak, told TRT World that RS has to follow the Sarajevo Constitutional Court's decision because the country's federal system requires that.

"RS wants to act as an independent state in the country," adding "The decision which has been taken by the Banja Luka's Constitutional Court also violates the system of the Office of the High Representative."

Boşnak also said that the decision could also lay the constitutional groundwork for Croatians to celebrate their establishment day.

"The decision also might pose a threat to the state structure."

Bosnian politicians have called on the senior international official in Bosnia and Herzegovina, High Representative Valentin Inzko, to intervene and stop the referendum.

"This referendum can only be prevented by Valentin Inzko. We need a stronger reaction from the OHR [Office of the High Representative]," said Minhet Okic, a member of the Bosniak Party of Democratic Action.

Okic also said the decision could be appealed but at the end, the appeal will fail, and Inzko is the only person who can block the referendum decision. "I do not see any other alternative," he said.